Process for the manufacture of compounds of the ethylene series substituted by an aromatic residue



Patented June 18, 1935 UNITED STATES PROCESS FOR THE MANUFACTURE OF COM- POUNDS OF THE ETHYLENE SERIES SUB- STITUTED BY AN AROMATIC RESIDUE Willi Krey, Uerdingen, Germany, assignor to I. G.

Farbenindustrie Aktiengesellschaft, Frankforton-the-Main, Germany No Drawing. Application January 11, 1932, Serial No. 586,083; In Germany January 17,

23 Claims.

The present invention concerns the manufacture of compounds of the ethylene series of the general formula R4 wherein R1 represents an aromatic radical, such as a phenyl radical, a substituted phenyl radical, a naphthyl radical or a substituted naphthyl radical etc., R2, R3 and R4 being a hydrogen atom or a substituent such as a halogen atom, an aryl radical or a substituted aryl radical, an alkyl radical etc.

In accordance with the present invention the splitthg of l-chloro-l-arylethanes into hydrochloric acid and an aromatic ethylene compound can be accomplished in a very simple and economical manner by heating the chloro compounds with acid-reacting compounds containing oxygen, 'the acid reaction of which is due to the presence of a dissociable hydrogen atom attached to an oxygen atom, such as e. g. boric acid, arsenic acid, palmitic acid, mono-chloroacetic acid, benzoic acid, p-chloro-benzoic acid, a-naphthalene carboxylic acid, salicylic acid, benzene sulfonic acid, phenol, chlorophenol, picric acid and the like. In this process the weaker acids preferably organic acids soluble in the reaction mixture are made use of with advantage as they do not cause polymerization of the resulting aromatic vinyl compound or only do so to a slight extent. Such polymerization can likewise be suppressed by distilling oil the aromatic vinyl compound at the rate it is produced and by adding'to the reaction mixture substances which retard polymerization such as nitro-benzene, nitro anthraquinone etc.

For the purpose of this invention l-chloro-larylethanes of the general formula R1 being an aromatic radical, such as e. g. a phenyl radical, a substituted phenyl radical, a naphthyl radical or a substituted naphthyl radical etc., R2, R3 and R4 being a hydrogen atom or a substituent such as a halogen atom, an aryl radical or a substituted aryl radical, an alkyl radical etc., can be used. It being noted that the l-chloro-l-arylethanes of the general formula in which R1 represents a phenyl radical or asubstituted .phenyl radical and R2 represents a hydrogen or a chlorine atom are especially suitable for the, manufacture of the corresponding aromatic vinyl compounds in accordance with the present invention.

A special advantage of the new method 'of working consists in the fact that much less than the quantity of the above acids is required than is equivalent to the chloro compound, e. g. 110% by weight calculated on the amount of the chloro I compound used. The acids are not used up but act catalytically.

The hydrochloric acid liberated can be employed with advantage for the manufacture of new quantities of the chloride serving as the starting material for the above described process, for example in accordance with the co-pending application Serial No. 563,462.

The process is further illustrated by the following examples without, however, restricting the invention to the particular quantities, temperatures or other conditions; the parts being by weight:

Example 1 Example 2 500 parts of a-chloro-ethylbenzene are mixed with 10 parts of a-naphthalene carboxylic acid. Heating this mixture at a temperature of to 140, the evolution of hydrochloric acid commences. The reaction proceeds quickly at 150 to 200 C. The resulting styrene is distilled oflf as described in Example 1. Then the distillate is fractionated after washing with a solution of sodium carbonate as mentioned in Example 1. About 75% of the calculated quantity of styrol is obtained.

Example 3 Instead of the rat-naphthalene carboxylic acid in Example 2 10 parts of mono-chloroacetic acid are used. About of the calculated quantity of styrene is obtained.

Ewample 4 2. The process which comprises heating achloro-ethyl-benzene with benzoic acid.

3. The process which comprises heating achloro-ethyl-benzene with benzoic acid at a temperature of about to about 200' C.

4. The process which comprises heating achloro-ethyl-benzene with benzoic acid and an-' thraquinone at a temperature of about 130 to about 200 C.

5. The process which comprises heating achloro-ethyl-benzene with monochloroacetic acid at a temperature of about 130 to about 200 C.

6. The process which comprises heating an 1- chloro-l-arylethane of the general formula:

R1 being a phenyl radicle or a naphthyl radicle, R2, R3 and R4 being a hydrogen atom or a halogen atom with an organic acid-reacting compound containing oxygen.

7. The process which comprises heating an 1- chloro-l-arylethane of the general formula:

R: R: R1-R4 R1 being a phenyl radicle or a naphthyl radicle, R2, R3 and R4 being a hydrogen atom or a halogen atom with benzoic acid.

8. The process which comprises heating an 1- chloro-l-arylethane of the general formula:

- mil...

in which R1 represents a,phenyl radical and R2 represents a hydrogen or a chlorine atom with an organic acid-reacting compound containing oxygen.

9. The process which comprises heating an l-chloro-l-arylethane of the general formula:

in which R1 represents a phenyl radical and R1 represents a hydrogen or a chlorine atom with benzoic acid.

10. The process which comprises heating an 1-cliloro-larylethane of the general formula R1 being a phenyl radicle or a naphthyl radicle, R2, R3 and R4 being a hydrogen atom or ahalogen atom with an acid-reacting compound containing oxygen which does not cause a substantial polymerization of the resulting aromatic vinyl compound.

11. The process which comprises heating an l-chloro-l-arylethane of the general formula in which R1 represents a phenyl radicle and R2 represents a hydrogen or a chlorine atom with an acid-reacting compound containing oxygen which does not cause a substantial polymerization of the resulting aromatic vinyl compound.

12. The process which comprises heating alpha-chloro-ethylbenzene with an acid-reacting compound containing oxygen which does not cause a substantial polymerization of the resulting aromatic vinyl compound.

13. The process which comprises heating alpha-chloro-ethylbenzene with an acid-reacting compound containing oxygen which does not cause a substantial polymerization of the resulting aromatic vinyl compound and a substance retarding polymerization.

14. The process which comprises heating an l-chloro-l-aryl-ethane of the general formula:

R1 being a phenyl radicle or a naphthyl radicle, Ra, R3 and R4 being a hydrogen atom or a halogen atom with a compound containing oxygen, said compound showing a weak acid reaction.

. 15. The process which comprises heating an 1-chloro-1-aryl-ethane of the general formula:-

R1 being a phenyl radicle or a naphthyl radicle,

R2, R3 and R4 being a hydrogen atom or a halogen atom with a compound containing oxygen, said compound showing a weak acid reaction and being soluble in the reaction mixture.

16. The process which comprises heating an l-chloro-learylethane of the general formula:

r-E-E-Ri 1 ii in which R1 represents a phenyl radicle and R2 represents a hydrogen or a chlorine atom with a n ur compound containing oxygen, said compound showing a weak acid reaction.

17. The process which comprises heating an l-chloro-l-arylethane of the general formula:

in which R1 represents a phenyl radicle and R2 represents a hydrogen or a chlorine atom with a compound containing oxygen, said compound showing a weak acid reaction and being soluble in the reaction mixture.

18. The process which comprises heating alpha-chloro-ethyl-benzene with a compound containing oxygen, said compound showing a weak acid reaction.

19. The process which comprises heating al-' pha-chloro-ethyl-benzene with a compound containing oxygen, said compound showing a weak acid reaction and being soluble in the reaction mixture.

20. The process which comprises heating alpha-chloro-ethyl-benzene with a compound containing oxygen, said compound showing a weak acid reaction and a substance retarding polymerization.

21. The process which comprises heating alpha-chloro-ethyl-benzene with a compound containing oxygen, said compound showing a weak acid reaction and being soluble in the reaction mixture, and a substance retarding polymerization.

22. The process which comprises heating an l-chlor-l-arylethane of the general formula in which R1 represents a phenyl radicle and R2 represents a hydrogen a chlorine atom with an acid reacting compound containing oxygen which does not cause a substantial polymerization of the resulting aromatic vinyl compound, and the acid reaction of which is due to the presence of a dissociable hydrogen atom attached to an oxygen atom. WILLI KREY. 

